light requirement ?

[jeepjon]

From what I've read, the Deresa's are pretty low light requirement, I've kept one of them under some minimal lighting and he did fine...that was about three years ago in one of my past setups. I had 110 watts on a 20 gallon and the deresa was growing like a weed when I took it out of there. Anyway...back to bussiness, The tridacna gigas are from deeper waters, but they grow HUGE. I hear the squamosa aren't a super light requiring species. I know the deresa's like to be on the ground, though, so that's a consideration. You might want to try a nice squamosa, they're pretty and not as demanding, according to Sprung and Delbeek, at least.

[Geoff]

thanks!

so how do you know if a clam is not getting enough light? i have so far been very carefull about placment and the clams i have now have oodles of light. just wondering what the warning signs are for clams.

G~

[Flatfish]

As you likely know it’s zooxanthellae cells in part that give a clam its nice colors. Brightly colored clams like T.maxima and T.crocea zooxanthellae have adapted to very intense light and UV using the bright colored cells to protect the clam’s tissue. Under sub-par lighting the brightly colored zooxanthellae will be expelled. What’s left are the darker colored (brown-ish) zooxanthellae. So under inadequate lighting the clam will first lose its bright coloring to a darker color. If the conditions are not corrected the clam will also lose the brown zooxanthellae. If the clam’s conditions aren’t corrected its brown-ish color will start to fade. This is called bleaching. When a clam starts to bleach it’s usually too late to save it.

Clams will also darken when exposed to too much lighting. What happens here is that the numbers of zooxanthellae cells increases to protect the clam’s tissue. The clam till also not extend its mantel as much as would do normally. You may see this happen if a clam is placed too high in a tank. This is a clue to move it down.

Here are some good articles if you're interested:

http://animal-world.com/encyclo/reef/clams/tridacna.htm

Joe

[Reefdude5]

Good summary Joe! I like this discussion, we should also discuss weather phyto is necessary for small clams....

[Geoff]

sweet info Joe!!

thanks,

G~

[aliendomain]

I've had them about a month now...I don't feed any phyto as I was advised against it for adult clams...they're about 4-5" clams. They seem to be really happy so far, they open up a lot and have a lot of mantle extension. They aren't anything super fancy, but they are croceas.

I think that in a tank as shallow as yours you can be successful with maximas and croceas, but you will have to keep them for at least six months before you know that you are successful.

[aliendomain]

Sorry double post